[@LloydTurquoise] I was thinking the war would be support for a foreign noble. Though at this point it would be minor support. The noble in mind is mentioned in what I've written so far in the history. His name is Godric. During his time there were two other kingdoms. One to the east, and one to the north. His would be in the southwest. The revolt happened due to an empty treasury of the reigning line. It's highly possible that once Godric got things running again he'd try and invade and take a small province of the Eastern kingdom. It's quite possible he would offer the Vohemian monarch of the time some land in this Eastern kingdom if they would help him in his war. The current borders could be fairly recent, with the expulsion of Vohemian nobility in this place taking place say... 100 years ago? 

Perhaps after a long and bloody conflict? I'd also be open to the nobility leaving peacefully, or anything you yourself may have in mind.

In addition, is there any possibility of the royal lines mixing? Edwynn has four daughters after all, and I'm sure he'd have loved to have used them as bargaining chips.

These are the things I've been thinking of. If you have any other ideas, or want to revise what I've written down, I am more than open to discussion.